Conventional electrical power steering systems for use in passenger cars and small trucks use belt-driven recirculating ball nuts to convert rotational movement of the electric motor to linear movement of the rack bar. Those recirculating ball nuts are sensitive to distortion and angular displacement of the rack relative to the ball nut, which results in increased friction and hence, a feeling of “sticky” steering and reduced efficiency of the electric power steering system. In order to avoid this distortion, the contact surfaces on the gear housing and the vehicle frame it is mounted to, are precisely machined, which is an undesired, expensive manufacturing operation on the frame and on the steering gear housing. In some designs, it is not possible to position all mountings on one casting of the gear housing, so a certain inaccuracy remains even after machining and leads to the “sticky” steering feel. In some other cases, the subassembly of steering gear and frame is distorted when being assembled to the vehicle because of vehicle body tolerances, placing the housing under stress/tension.
However, a steering gear housing which is under stress during operation may have a negative effect on the steering sensation which is perceived by a driver of the vehicle, in particular, for example, in the case of electro-mechanical steering systems in which an electric motor is in operational engagement by means of a ball screw with the toothed rod of the steering system since ball screws can react in a particularly sensitive manner to mechanical distortions.
Against this background, an object of the present disclosure is to provide a mounting arrangement for a steering gear housing and a vehicle in which stress-free or substantially stress-free securing of the steering gear housing to a bodywork component of the vehicle is possible, so that there are no negative effects on the steering sensation perceived by a driver of the vehicle from a steering gear which is secured to the bodywork component of the vehicle. In addition, the mounting arrangement is intended to ensure a secure and fixed arrangement of the steering gear housing to the bodywork component of the vehicle.